Reidar Skau (26 December 1893 – 19 February 1975) was a Norwegian judge.
He was born in Christiania, a son of Aksel Olaf Skau and Anna Karoline Dahl.
He graduated as cand.jur.
in 1920, and later practiced as a barrister.
He was appointed Justice of the Supreme Court of Norway from 1945 to 1963.